McQuay MWM - LED Diagnosis: Ceiling Exposed D;E Series

MCQUAY Service Guide Book Diagnosis
49
Ceiling Exposed D / E Series Model
Model Board Handset
MCM 20/25/30/40/50D/DR L208A G17 / SLM3 / Netware 3 / SLM8
MCM 15/20/25/28E/ER L208A G17 / SLM3 / Netware 3 / SLM8
COOL
(Green)
DRY
(Orange)
FAN
(Green)
HEAT
(Red)
Error Code
(SLM3 /
Netware 3)
Operation / Faulty
Indication
Action
- Cooling mode -
- Dry mode -
- Fan mode -
- Heating mode -
-
Auto mode in
cooling operation
-
-
Auto mode in
heating operation
-
E1
Room air sensor
contact loose / short
Check room sensor
connection / change room
sensor
E2
Indoor coil sensor
contact open
Check indoor coil sensor
connection / change indoor
coil sensor
E3
Outdoor coil sensor
contact open
Check outdoor coil sensor
connection / change
outdoor coil sensor
E4
Compressor
overload protection /
Indoor coil sensor
short / Outdoor coil
sensor short
If running ampere highly
increase, change the
compressor. If not, replace
the coil sensor
E5 Gas leak
Check for leakage & repair
/ Top up refrigerant
E7
Outdoor coil sensor
exist (MS model)
Remove outdoor coil
sensor
E8
Hardware error (tact
switch pin short)
Replace the tact switch
control board
/
ON ON or OFF BLINKING
Blink Heat, Cool, follow by Fan, Dry